Putting To Rest The Myth That Dating Dinosaur Fossils With Carbon 14 Shows The Method is Flawed Or Dinosaurs Are Young
Creationists bring up Carbon 14 dating of dinosaur bones all the time. This shows a lack of basic understanding of how the method is used and what material it can be used to date. Carbon 14 is used to date things that were once living and in equilibrium with the atmosphere.
Here is a brief explanation of how the method works from http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/cardat.html
"Cosmic ray protons blast nuclei in the upper atmosphere, producing neutrons which in turn bombard nitrogen, the major constituent of the atmosphere . This neutron bombardment produces the radioactive isotope carbon-14. The radioactive carbon-14 combines with oxygen to form carbon dioxide and is incorporated into the cycle of living things."
"From the known half-life of carbon-14 and the number of carbon atoms in a gram of carbon, you can calculate the number of radioactive decays to be about 15 decays per minute per gram of carbon in a living organism."
"Carbon-14 decays with a halflife of about 5730 years by the emission of an electron of energy 0.016 MeV. This changes the atomic number of the nucleus to 7, producing a nucleus of nitrogen-14. At equilibrium with the atmosphere, a gram of carbon shows an activity of about 15 decays per minute.
The low activity of the carbon-14 limits age determinations to the order of 50,000 years by counting techniques."
Some creationists seem to understand that rocks and minerals cannot be dated using the Carbon 14 technique. This is a quote from the CMI website and it is accurate:
"Obviously this only works for things which once contained carbon—it can’t be used to date rocks and minerals, for example. We know how quickly C14 decays, and so it becomes possible to measure how long it has been since the plant or animal died." http://creation.com/carbon-14-dating-explained-in-everyday-terms
It seems what creationists fail to understand is dinosaur bones are permineralized or at the very least, partially permineralized, and therefore they no longer qualify as "once living material." Once the original material has been replaced with minerals it cannot be dated using the Carbon 14 method. Even soft tissue has shown to be preserved with minerals such as iron rendering the method useless for dating.
Why does dating sedimentary rock or these fossils often show traces of carbon 14? Because they have been exposed to the environment. Sedimentary rock can contain pockets gas that would reflect the atmosphere when the rock was formed. Permineralized fossils could also contain trace amounts of C 14, but it would no longer be in equilibrium with the atmosphere from the time the animal died and test results would typically show ages in the 20,000 + to 45,000 year range. This is not a problem with more recent bones that are not permineralized.
I hope this answers some YEC questions about why scientists do not date dinosaur bones with the Carbon 14 method. It is not because they are afraid it would show the dinosaurs lived only thousands of years ago, it is because they know the test cannot be give accurate results since the material being tested was not actually "once living" after minerals replaced the actual bone.